What is Taxonomy
The general meaning of Taxonomy is the science of classification. In Drupal it refers to the method by which your web site content is organized, using different types of relationships between the terms.
There are several terms that need to be explained in order to better understand the Taxonomy functionality.
Term - The term that is used to describe content. In some articles it is referred to as descriptor.
Vocabulary - The vocabulary is a list of multiple terms related in some way.
Taxonomy - The categorization of the content in a hierarchical structure.
Tagging - The process that associates a term with the content on your Drupal web site.
For more information on how to work with Drupal Taxonomy you can refer to the following tutorials: